Children with special needs require complex, individualized therapy to maximize their long-term quality of life. One subset of children with special needs includes those with both mental retardation and deafness. Currently, there is little compelling evidence supporting the idea that cochlear implantation provides benefit to children that don't have the cognitive potential to develop normal speech and language. As well, pediatric cochlear implantation does entail a certain level of risk. Therefore, many centers will not implant deaf children if they have severe cognitive delays. Instead, the most popular method of treating hearing loss in children with mental retardation is to use powerful hearing aids to achieve vibrotactile sensations or acoustic sensitivity to low frequency sounds in a similar fashion to what was done for all deaf children prior to the development of cochlear implants. The typical clinical outcome is sound awareness, i.e. the ability to detect environmental sounds and voices. A cochlear implant can improve auditory thresholds and word recognition ability, but because of the lower intelligence of patients with mental retardation, this value of this additional information is questionable. Since, it is unknown whether treatment with hearing aids or a cochlear implant is more suitable in this population; this question is best answered by a randomized clinical trial. Our preliminary data demonstrate that linguistic and cognitive development increase in this population of children after cochlear implantation. Based on these retrospective data, we hypothesize that development and quality of life will improve more in deaf children with mental retardation when treated with a cochlear implant compared to those treated with hearing aids. We will perform a prospective, randomized clinical trial to answer the question of which intervention provides more benefit to this population of children using validated, norm-referenced tests. All children eligible for cochlear implantation seen at Texas Children's Hospital will undergo a cognitive evaluation. Patients that meet the criteria for mental retardation will be given either hearing aids or a cochlear implant and followed longitudinally for two years. If our hypothesis is correct and cochlear implants significantly improve development and quality of life in deaf children with mental retardation, our study will provide essential evidence to support clinical decision-making in this population. Thus, our long-term goal is to develop guidelines that may help when selecting a treatment for hearing loss in a child with mental retardation. This proposal is significant because children with special needs are deserving of evidence upon which to base treatment decision-making, but remain under-represented in the medical literature and are often not studied. This research is designed to meet the criteria for the NIH roadmap because it will generate this type of objective evidence that can directly improve patient care. PUBLIC HEALTH RELEVANCE: This research is relevant to human health because it will provide evidence to answer the question of whether to treat a deaf child with mental retardation with a cochlear implant or hearing aids.